Allometric equations for below-ground biomass of four key woody species in West African savanna-woodlands

Jonas Koala, Louis Sawadogo, Patrice Savadogo, Ermias Aynekulu, Janne Heiskanen, Mohammed Saïd

Research output: Contribution to journalArticleScientificpeer-review


Accurate estimates of both above-ground biomass (AGB) and below-ground biomass (BGB) are essential for estimating carbon (C) balances at various geographical scales and formulating effective climate change mitigation programs. However, estimating BGB is challenging, particularly for forest ecosystems, so robust allometric equations are needed. To obtain such equations for savanna-woodlands of the West African north sudanian zone, we selected four common native woody species (Anogeissus leiocarpa (DC.) Guill. & Perr., Detarium microcarpum Guill. & Perr., Piliostigma thonningii (Schumach.) Milne-Redh. and Vitellaria paradoxa C. F. Gaertn.). At two sites in Burkina Faso, we determined the BGB of 30 trees of each of these species by excavation, and measured various above-ground dimensional variables. The root: shoot ratio varied widely among the species, from 0.1 to 3.4. Depending on the species, allometric equations based on stem basal area at 20 cm height, basal area at breast height and tree height explained 50-95% of the variation in BGB. The best generic equation we obtained, based on basal area at 20 cm, explained 60% of the variation in BGB across the species. Three previously published generic allometric equations underestimated BGB by 8 to 63%. The presented equations should significantly improve the accuracy of BGB estimates in savanna-woodlands and help avoid costly needs to excavate root systems.
Original languageEnglish
Article number1631
JournalSilva Fennica
Issue number3
Number of pages15
Publication statusPublished - 22 May 2017
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 4112 Forestry

Cite this